From Longman Dictionary of Contemporary Englishhead of water/steamhead of water/steamTPpressure that is made when water or steam is kept in an enclosed space → head
Examples from the Corpus
head of water/steam• But there is already a head of steam in parliament to make the proposed voluntary takeover code legally binding.• And he's just getting a head of steam.• By 1921 indeed frustration with coalition was building up such a head of steam as seriously to threaten its future.• The Siporax is only half submerged, so that a head of water never covers the biological media.• His friends viewed the affair with interest as it gathered a fair head of steam.• The bull market in bonds finally lost its head of steam.• Para Handy raises a new head of steam Nan Spowart reports on the re-creation of a West coast legend.• A big crowd started to gather as Greg got on a real head of steam. 